FR2477071A1 - PRINTER BY POINT MATRICES - Google Patents

Abstract

THE INVENTION RELATES TO DOT MATRIX PRINTERS. IT RELATES TO A PRINTER WHICH INCLUDES A HIGH NUMBER OF PRINTING ELEMENTS, ALIGNED IN AN INCLINED DIRECTION OF THE PRINT DIRECTION, SO THAT THE CHARACTER RESOLUTION CAN BE EXCELLENT FOR MAXIMUM CHARACTER HEIGHT AND MINIMUM DIMENSION OF PRINTING ELEMENTS. APPLICATION TO THE PRINTING OF SMALL JAPANESE AND CHINESE CHARACTERS.

Description

The present invention relates to dot matrix printers,

  intended to write letters, numbers and other graphic symbols with a resolution better than that obtained with symbols having a total height of less than 4 mm.

  In particular, the invention relates to printing heads

  with adjacent printing elements whose

  centers are spaced from the distance imposed by the di-

  meters, however, these being offset from each other both horizontally and vertically so that lines are visibly separated.

  points can be printed in more

  approached than that which can be obtained considering

  the spacing of the centers of the elements.

  Printers are commonly used for

  matrixes of points, with calculators and computers

  and other electrically controlled devices for printing alphanumeric information. Normal Arabic numerals and classic letters in Roman characters, both upper and lower case, can be printed legibly with a matrix having 7 x 9 points or even 5 x 7 points arranged in checkerboard. A 7 x 9 point arrangement allows the printing of up to 4 distant vertical lines and 5 horizontal horizontal lines when the dots have a maximum spacing,

  but this small number of lines is not enough for

  a clear and even readable reproduction of the approximately 2,000 Chinese characters that are used most

  fluent in Japanese language printing. One

  see minimal resolution of about 13 x 13 points is -

  necessary and the arrangement preferably has at least

17 x 17 points.

  An example of a print head does not have the total number of printing elements suggested by the multiplication of these two numbers that define the arrangement. A 5x7 type arrangement does not have five columns of seven print elements and an arrangement

  of 7 x 9 points does not have seven columns of nine elements.

  On the contrary, in a matrix with normal spacing,

  a thirty-five point checkerboard pattern, only one vertical column of seven print elements is

  used, the head moving in five

  Elemental zontals for printing the thirty-five point pattern, a 7x9 dot printer having a print head having only one column

  vertical of nine printing elements. The head of

  pressure moves seven elementary steps horizontal-

  when printing a checkerboard arrangement to

sixty-three points.

  There are also printers that form half-space dies in which the head moves a distance corresponding to half the width of a point. However, the speed of movement of the head called scanning speed, is too great

  so that dots can be printed with

  because the print elements can not

  be ordered with the necessary speed of repetition.

  Points can * be printed for all posi-

  which do not overlap. A disadvantage of

  An apparatus employing such a half-space matrix is such that a half-space 9 x 7 matrix can form only three separate vertical lines and not five as in the use of a

matrix with normal space.

  The number of non-overlapping points that can be formed in a given space is determined by

  the dimension of the impression given by the elements.

  The points are essentially circular in shape

  and the diameter of the printing elements is usually

  the essential restriction limiting the reduction

  point spacing. An advantageous example of stamp dot matrix printing elements is a ballistic needle or wire which is struck at a first end by an armature of an electromagnet so that it is projected. forward like an arrow and prints a point before bounce facilitated by a spring. It is essential that the striking of the core of the electromagnet causes a displacement

  axial axis of the needle and not simply its deflection.

  The smallest needle diameter that can be used for an industrially acceptable time is about 0.35 mm and usually the front parts

  the complete number of needles, seven or nine usual

  They are supported side by side in a support of suitable material, for example alumina or synthetic ruby, having a corresponding number of very polished holes and forming a very close line of tróus. The diameter of each hole is about 0.37 mm and the centers are about 0.37 mm apart. Needles

  whose diameter is less than approximately 0.35 mm,

  approximately 0.2 mm were used but they

  require a support sleeve that limits the

possible.

  The spacing of the centers of the adjacent holes of the support determines the distance between the centers of the points of the adjacent horizontal lines so that

  adjacent points, vertically distant, are not -

  not significantly recover and the number of lines

  to be formed in a given vertical space is

  so limited. The support hole line is normal-

  perpendicular to the direction of movement by the elementary step of the print head, and is therefore

normally vertical.

  In some printheads, the line of holes in the media is tilted slightly so that the letters are tilted as handwritten letters are frequently, but the spacing of the centers of the holes in the media of these heads is large enough to that the points formed by the adjacent needles do not overlap noticeably. The British patent

  No. 1,343,570 describes such an arrangement.

  The invention essentially relates to a print head for printing Chinese symbols used by the Japanese people and called "kanji". Many Kanji symbols are very complex and require up to twenty strokes and more for one

  only symbol. In addition, the Japanese Government has

  that the height of the Kanju symbol should not exceed

  3.7 ram, in the current applications of telecommunica-

  and computers. A Kanji character is normally housed

  in a square zone, and the resolution must be

  about the same in horizontal and vertical directions.

  The lower limit of readability, for the most complex kanji symbol, requires a matrix of points

  approximately 13 x 13 points at normal spacing,

  to form at least seven horizontal lines and seven

  vertical lines. Matrices with better resolution

  are desirable so that readability is

increased.

  According to the invention, print elements of a dotted dot print head are arranged so that the adjacent elements are offset both horizontally and vertically with respect to one another so that the centers of the horizontal lines points are closer together as possible when the same elements form the

  vertical column the least bulky possible.

  - The fact that the horizontal lines of dots formed by the adjacent printing elements may overlap partially but by less than half, give the horizontal lines a width greater than the minimum width of the white space between two lines

  horizontal, but it is not necessary that this

  white space is as wide as the printed lines, as long as it is clearly visible as separation

  between the lines. In addition, there are many

  even in a complex kanji symbol, in which

no point is necessary.

  The complexity of the Kanji symbols makes it desirable

  table the use of half-space matrices.

  The head may have instead of thirteen

  printing elements at least in a print head

  to form each symbol entirely in a page scan, seven or more elements of normal types so that the upper or lower half of

  each symbol of a line is printed during a

  the other half being printed during scanning

  following which can be done in reverse. The im-

  Two-way pressure is common and the memory systems used in these printers can delay the activation signals of each element.

  that the horizontal offset is compensated.

  Separate supports can be used for several sets of needles so that there is sufficient space in the housing of the dispensing device.

  action of a relatively large number of needles.

  Separate holders of multiple needles can be accurately and precisely offset

  compared to others so that all horizontal lines

  zontales are printed in a single sweep of the

  printhead and without the paper having to move

  by step less than one line at a time.

  Other features and benefits of

  the invention will emerge more clearly from the description which

  will follow, made with reference to the accompanying drawings in which

  Figure 1 is a perspective of a printer

  dot matrix mantle made according to the invention;

  Figure 2 is a simplified schematic diagram of a

  ballistic stroke printing system, used conventionally and in the context of the invention; FIG. 3 shows in enlarged form the front end of the print head of FIG. 4 and a line of dots, representing the impression of a horizontal line; Figure 4 shows an arrangement of printing elements of known type; Fig. 5 shows the geometrical arrangement of an arrangement of printing elements according to one embodiment of the invention; Fig. 6 is a side elevation of a ballistic stroke printing needle made in accordance with one embodiment of the invention; and FIGS. 7A and 7B show variants of printing heads according to the invention, having two sets

  offset printing elements.

  Figure 1 shows an example of a printer

  it by dot matrices intended to print sym-

  graphic bots comprising letters, numbers, punctuation marks and other symbols on a recording medium, the most common example being paper. In the printer 11, the paper 12 passes

  on a cylinder 13 arranged in front of a printing head 14.

  It moves laterally on two guide rods

  of which only one 16 is shown in the drawing. The function

  the printing head when it prints symbols and when it moves along the guide rods, and the operation of the cylinder that feeds the paper into the printer 11, is electrically controlled, either by means of of a keyboard 17 either by

  electrical signals from other sources.

  Unlike a typewriter that

  prime each symbol as a whole in a single run, a dotted dot printer builds each symbol by printing an array of points produced each at a particular location relative to

  other points necessary for a given symbol

  conch. The points that form a symbol are not all printed simultaneously, except for the simplest symbols such as the point, but are printed in a particular sequence. Each dot is printed by a print element and the print sequence of the dots depends on the location of the print elements relative to one another. The front or print end of each item is at one location

identified by reference 18.

  Fig. 2 shows a current arrangement of the printing elements. The element is formed by a

  fine wire or a needle 19 carried by a sup-

  front door 21 with rubies and a rear guide 22. The

  The front 23 of the needle 19 is turned towards the paper 12, wound in part around the cylinder 13. The paper may be of a type that darkens when pressure

  only is applied, as in the case of self-adhesive

  copying or, as shown in Figure 2, it may be a normal paper that requires the interposition of an ink ribbon 24 guided in the space between

  the paper 12 and the front end of the needle 19.

  The needle 19 moves to the left in the arrangement of Figure 2 when struck by the armature 26 of an electromagnet 27. The latter has a U-shaped core 28 formed of low alloy steel or another weakly magnetic material, whereas a coil

  29 command is placed around a branch of the kernel.

  The armature 26 is articulated at the end of the other arm and is pushed clockwise by a spring 31. The needle 19 is resiliently pushed towards the right by a spring 32 which is compressed between the plate 22 and a necklace 23 attached to the needle near

its rear end 34.

  The slight curvature of the needle 19 is due to the fact that it is only one of the needles of a

  group consisting of 7 or 9, arranged so that the extremes

  mited before are aligned and parallel or

  parallel as possible. Electromagnets of the different

  needles require much more space so that the back ends of the needles part in an arc so that the curvature of the needles is

miniLa the.

  The arrangement of the needles of FIG. 2 is a ballistic stroke system since each needle, like the needle 19, receives a net force of shock applied by the armature 26 when the electromagnet 27 associated with the needle is excited. The counterclockwise movement of the armature 26 is limited but the force due to the shock is large enough that

  the needle moves to the left despite the compres-

  increasing and simultaneous increasing spring 32, until the front end 23 strikes the tape 24 and presses it against the paper 12. The spring 31 brings the armature 26 by pivoting clockwise just after the shock against the rear end 34 of the needle 19. When the needle has traveled its ballistic stroke forward under the action of this shock and caused the printing of a point on the paper 12, the needle bounces to the right, and the return is facilitated by

  the energy stored in the spring 32.

  Dot matrices may be formed in other ways, for example by

  ballistic, by ink projection, by

  or otherwise, but ballistic systems

  are used extensively in practice and are considered in.

  the following description is purely illustrative,

  because the invention is not limited to this single

  tion. Figure 4 shows in enlarged form the support 21 with rubies and the front ends 23a to 23i of nine needles 19a to 19i. The support 21 may be formed of a synthetic ruby and, according to a common technique,

  it consists of two parts 21a and 21b which are symmetrically

  - from each other. The guide surfaces of the needles 19a to 19i are curved cavities 36-a to 36i

  one edge of part 21a and corresponding curved cavities

  36a 'to 36i' of the edge opposite part 21b.

  The diameters of the orifices delimited by each pair of cavities are slightly greater than the diameters of the needle guided by the corresponding pair. For example, a diameter commonly used for the needles is about 0.35 mm and the diameter of the orifice of the

  port that houses the needles of this dimension is.

  0.37 mm. The distance separating the centers of the adjacent orifices is also 0.37 mm, that is to say that

  distance corresponds to the spacing of the centers of the

  adjacent guilleas. It is theoretically possible for each of the cavities 36a to 36i and 36a 'to 36i' to be in a semicircle, but it is then necessary for the material of the support to thin up to zero width at the edges opposite the two parts 21a. and 21b. At this level, the material would wear excessively and the arcs that delimit the cavities are therefore limited to less than

  1800. However, the curved surfaces that remain

  sufficiently leave the space left to the needles 19a to 19i so that the adjacent needles can not

rub against each other.

  The size of each point is determined

  This is caused by the diameter of the needles but the texture of the paper surface on which dots are printed makes the configuration and to some extent the size of the dots inaccurate. The profile of a point, indicated by a magnifying glass, is relatively coarse so that the precise measurement of the diameter is not possible. The dimension of each point is also

  affected by the nature, hardness and thickness of the

  pier as well as the number of copies, the ambient conditions, the nature of the ribbon used and the ink ribbon, as well as other parameters. These do not have the same effect on the dimension of the points, and the

  most important factor is the diameter of the needle.

  When the known structure represented on the

  FIG. 4 scans the paper 12 along a perpendicular line

  at the needle line 19a to 19i as shown in FIG. 3, and when two needles 19a and 19c separated by the needle 19b are repeatedly controlled, two horizontal lines 37 and 38 of dots are formed with a gap 39 between them. The dots have a diameter of about 0.35 mm corresponding to the size of the needles and the centers are separated by

  0.74 mm. To the naked eye, the points of a line tend to

  In this way, each of the lines 37 and 38 appears to have a width of about 0.35 mm, and the space between the two lines is about 0.39 mm. The maximum height of a symbol printed by a nine-needle structure of the type shown in FIG.

  of 0.37 (N-1) + 0.36 mm or 2.94 mm

  takes at best five lines visibly separated from points.

  When four more needles are added so

  that seven lines can be printed, the maximum height

  symbol is 5.6 mm, that is, it is

  well above the size chosen by the Government.

  as previously stated.

  Figure 5 shows a geometric analysis of a modified printing structure that makes it possible to print at least seven horizontal lines in a space having a total height of 3.7 mm. A structure having N needles 41A, 41B ... 41 (N-1), 41N is arranged so that the needles are inclined at an angle e with respect to the horizontal. The hatched lines

  42 and 43 printed by the needles 41A and 41C are

  diquées. These lines are represented with a constant width but they are actually formed by dots in the same way as the lines 37 and 38 of Figure 3. All needles have the same diameter D and the width of each line is considered equal

  to D although the width may actually differ slightly

  the diameter of the needle. The width of the space 44 between the obviously closest lines-42 and 43 is called W. The width W is less than the width D of a line, unlike the space 39 separating the lines

  37 and 38 in Figure 3, but space 44 is still clearly

  visible, and the visibility of this space is a

  extremely important according to the invention.

  Figure 5 shows a vertical lapse V between two adjacent needles 41 (N-1) and 41N, and the same overlap exists between the adjacent needles of each pair. The distance between the centers of two adjacent needles, as indicated for the needles 41A and 41B, is equal to X and consequently the distance between the centers of the end needles 41A and 41N

is equal to (N-1) X.

  The vertical distance separating the centers of the adjacent needles is equal to the radius R of each reduced needle of the vertical overlap V, that is 2R-V. Like D = 2R, the vertical distance can be written as D-V. The total vertical distance between the slots of the hands 41A and 41N is (N-1) (DV) and the total height T of the highest symbol that can be printed is: T = (Nl) (DV) + 2R ( 1) Equation (1) can be rewritten in different forms:

T = ND - V (N-1) (2)

or

T = N (D-V) + V (3)

  The angle e is given by the relation: e = sin- 1 D-V (4) X The width.W is:

W = D - 2V (5)

  The width W of a space 44, expressed as a percentage of the width D of a line 42, is:

W% D - 2V

U = D (100) (6)

  Several numerical examples show the advantage

  offset the adjacent print elements both horizontally or more generally in the print direction, and vertically or

  general in inclined direction (usually perpendicular

  culairement) to the printing direction. For example, when using fourteen 41A to 41N needles having a diameter of 0.35 mm which is the diameter often used now and for some time to date, and for a center spacing of 0.37 mzii , you can print seven separate horizontal lines in

  a space with a maximum height of 3.7 mm, by deca-

  the adjoining needles at an angle e of about. This angle e is considered an absolute angle because the needle lines can be tilted upwards to the right as shown in FIG.

to the top left.

  The vertical coverage V of any two adjacent needles, for example needles 41A and 41B, is about 0.09 mm. The space W between two lines of points or horizontal lines 42 and 43 printed by

  any pair of adjacent needles in a first

  first group of first needles comprising alternating needles 41A, 41C ... is about 0.17 mm or about 47% of the width of any line such as line 42. Spaces such as space 44, between two horizontal lines distant, can be

  filled with the printing of dots with elements

  printing dies of a second group comprising the elements 41B, 41D, ... each of which can print a line of points centered between two lines on each side of

  these lines and with overlapping thereof.

  When any two points are to be printed in a vertical line despite the fact that the needles are staggered as shown in FIG. 5, a certain delay time must be maintained between the printing of these vertically aligned points. When the vertically aligned points are to be printed by adjacent needles 41A and 41B, the delay must be

  be connected to the magnitude X cos e, that is to say to the

  offset or horizontal movement between these points. When the dots printed by the furthest hands 41A and 41N are considered, the delay is

connected to (N-1) X cos e.

  The principle of the shift of the needles makes it possible even to use nine horizontal lines separated in a vertical height of 3.7 mm, with needles with a diameter of about 0.35 mm separated between center by a distance of about 0.37 mm. The angle e must be reduced to about 320 and the covering V is then about 0.16 mm or about 45% of the width

  of a line. The minimum net space between two visible lines

  separated by almost 11% of the width D

of a line.

  The diameter of the needles 41A to 41N is not necessarily 0.35 mm. However, in the case of nine separate horizontal lines and eighteen needles, the diameter of each needle must be less than about 0.39 mm because for the diameter V = D / 2 the width W becomes zero, that is to say that there is no space between

  lines 42 and 43 which must be visibly separated.

  The corresponding minimum limit value of e is a

not much less than 29.

  The reason for selecting even numbers of needles 41A to 41N, for example fourteen or eighteen,

  for the formation of seven or nine separate lines

  Many points such as lines 42 and 43 are that many existing dot-matrix printers have seven- or nine-pointed printheads, and it is desirable that the mechanism of these machines

  existing ones can be used with minimal revision.

  A simple tilt of the existing print heads with seven or nine needles or even just the support

  of rubies, allows the use of these heads for the

  pressure of the upper or lower half

  more or less a symbol at a given moment. In one variant, many symbols can be printed

  with the lower set of dots only.

  It may be desirable, in the general case, for printing half of a single symbol to be replaced by printing the upper or lower half of all symbols on a given line in a head scan stroke. printing the entire line, the paper then advancing the distance necessary to print the other half in a second scan, preferably in the opposite direction. In a variant, the head can be moved in place of the paper. The printing of alternating lines of symbols

  alphanumeric characters in opposite directions is a practical

  well known, and the circuits of memory and

  order for such bi-directional printing

  may be used for the printing of

half height symbols.

  Using the same needles twice in such bidirectional printing is equivalent to doubling the number of needles, and doubling any number indicates that the effective number can be even and not odd. Paper can advance

  just enough so that the upper needle im-

  priming the top line of the lower half of the symbols falls exactly on the positions of the needle printing the bottom half line

  superior symbols. The advantage of the advance of the

  pier of this distance much less than half of the maximum height of the symbols is that the space W between the nearest visibly separated lines which are closest is increased, for example W is about 0.06 mm for seventeen needles 0.35 mm in diameter each but is only 0.04 mm for eighteen needles of the same size. Thus, space 44

  for an arrangement with seventeen needles would be approximately

  17% of the width of the line instead of

  11% for an arrangement with eighteen needles. The angle

would be about 340.

  Although a printing arrangement in which the actual or effective number of needles is even allows printing only the same number of lines visibly separated as the printing arrangement having one less needle, the extra needle allows greater spacing of a pair of lines than other pairs. Any pair can be chosen so that she

  gives this additional spacing which can be of

  geux for the improvement of the visibility of the symbol.

In a printing arrangement having a smaller number of needles, for example thirteen, the value of W for needles of diameter equal to 0.35 mm, is

  about 0.20 mm or about 56% of the

  a line. The angle O is then about 49.

  Where all the needles are to be used or at least available for the two halves of a symbol, the relative vertical displacement of the paper and the print head shall be equal to NX sin t Where the lower line of the upper half shall ensure a precise overlap of the upper line of the lower half, the vertical offset must be (N-1) X sin 6

equal to 2-

  Although this feature is not absolutely necessary, needles such as

  the needle 19 of Figure 2, are in the form of cylinders

  of circular section. The distance

  dicular to the axis of a needle, measured from one face to the other, is called "diameter" even if the cylinder does not actually have a circular section. When the diameter is made much less than about 0.35 mm, the needle tends to be too flexible so that it can

  flex under the shock of the armature 26. Another advantage

  According to the invention, the offset of the needles is that the reduction of the diameter of the front part of the needle near the end 23 between the support 21 and the ribbon

24, becomes reasonable.

  Figure 6 shows a needle 46 according to this variant. Its main part 47 has a diameter

  uniform body size of about 0.35 mm although the di-

  body meter can be bigger and even a little smaller. The front cylindrical portion 48 has a smaller diameter which can be 0.2 mm and even less. This front portion must be long enough so that the shoulder 49 can not press the ribbon 24 (Figure 2) and the paper 12, its length being for example about 0.2 mi. The diameter of the end 51 must not be so small that the ribbon is pierced, and the portion 48 must be entirely in front of the support so that the shoulder 49 never penetrates into the support in which it could rub at the surface

  with excessive wear of it.

  When the needles having diameters ef-

  Fibers for printing points smaller than the body diameters, as in the case of the needle 46 of FIG. 6, are used for producing the needles 41A to 41N of FIG. 5, the visibility of the printed symbols can be further improved. . For example fourteen needles forming dots with a diameter of about 0.26 mm have no overlap V, although the body diameters are 0.35 mm and the axes are 0.37 mm apart. In such an arrangement, the space W is

  close to the diameter of the dots and the angle is approximately

45.

  When the arrangement comprises eighteen needles and when the printing diameters correspond to the formation of points of approximately 0.20 mm in diameter, there is no overlap V either and the angle e is

about 36.

  The angle f is calculated as if the apparatus of im-

  pressure included a delay line or another

  positive delay which can be set at any desired delay.

  If the device does not have a self-delay device, the printing of a vertical line of dots can be obtained by selecting the synchronization of the pulses which control the needles so that the pulses controlling any two needles intended to form vertically aligned points correspond to proper timing. This relationship over time must take into account the scanning speed of the print head and the vertical distance separating the two points. When a fixed synchronization system

  exists for the control of needles, the line of

  guilles may require a larger inclination, corresponding to a reduction in the absolute value of

  angle 6. The needles can then be more

  paced so that the horizontal lines of points

  awarded by adjacent pairs of needles

not recover excessively.

  Fig. 7A shows a print head

  52 having two supports 53 and 54 to rubies mounted rigidly

  on a chassis 56. The supports can be divided

  two parts similar to parts 21a and 21b

  4, and they can be held in place by clamping or otherwise fixed in the frame 56. The support 53 is a guide for nine needles 57a-57i and the support 54 constitutes a guide.

  for nine additional needles 58a-58i. Have them-

  guilles 57a to 57i are controlled by electromagnets 59a to 59i placed in a support 61 rigidly fixed to the frame 56. Similarly, the needles 58a to 58i

  are controlled by electromagnets 62a to 62i now

  naked in a support 63 which is also rigidly fixed to the frame 56. The latter is carried by rods such as

  the rod 16 of Figure 1 so that it can move-

  in translation in the directions indicated by the

double arrow 64.

  The supports 53 are arranged in the frame so that the lines of dots printed by the successive commands of the hands 57a and 58i or overlap - exactly or only overlap in the same way as the points formed by adjacent needles, if appropriate. . The supports 53 and 54 are also separated

  precisely in the horizontal direction so that a sym-

  can be printed with the eighteen

  guilles 57a to 57i and 58a to 58i, in the same manner as if the needles were placed in the same support. In this way, printing the upper half (approximately) of each symbol during the first scan

  of the print head and the lower half (

  viron) of each character during a second scan is superfluous. All the printing of each symbol is completed in one scan. In addition, the paper, like the paper 12 of Figure 1, does not have to advance a distance less than that which corresponds to a complete line, after each scan. It does not have to advance a small amount after alternate sweeps, and a slightly larger amount after others

sweeps that alternate.

  Figure 7B shows another embodiment of

  similar to that of Figure 7A. In FIG. 7B, only a front support 66 similar to the frame 56 and two ruby supports 67 and 68 similar to the supports 53 and 54 are shown. The electromagnetic activation devices are not shown but they can be identical to the devices 59a to 59i and 62a to 62i of Figure 7A. Supports 67 and 68 have needles 69a-69i and 71a-71i respectively, supported so

  they form parallel vertical lines. Contest

  at the needles 57a-57i of FIG. 7A, which are placed as close as possible, needles 69a-69i of support 67 of FIG. 7B and needles 71a.

  71i of the support 68 are separated by a sufficient distance

  that two adjacent needles, for example needles 69a and 69b, print separate lines

  visibly. The needles 71a to 71i have the same separation

  than the needles 69a to 69i but are staggered

  vertically so that the level of the center of a line.

  of points printed by successive control for example needles 71a is in the middle of the levels of

  centers of the dots printed by the needles 69a and 69b.

  The dots printed by the other needles are spaced

correspondingly.

  Obviously, the horizontal spacing of the pins 69a to 69i and 71a to 71i requires that a device

  delay command printing vertically aligned dots-

  by the two sets of needles. The supports 67 and 68

  can be separated by a distance allowing the use

  any convenient delay, but preferably

  ports 67 and 68, like the supports 53 and 54 of FIG. 7A, are as close as possible, since the relatively large section of the operating devices 59a to 59i and 62a to 62i shown in FIG.

7A must be considered.

  The particular numbers of printing elements and the dimensions indicated above are given in

  purely illustrative and non-limiting.

247707i

Claims (26)

  1. Printer, characterized in that it comprises a support device,   a first group of first elements of   pressure carried by the support device, these elements each having a certain body diameter and a front end having a printing area of a certain size,   intended to print a point having a predetermined diameter   every time a print element is ordered,   these elements being arranged along a line, the   the elements being oriented so that the centers of two lines of dots printed by two adjacent printing elements are separated by a distance greater than the diameter of the dots, but not between the centers of the adjacent elements being greater than twice the diameter of the body; significantly greater than twice this point diameter, and   a second group of second printing elements   carried by the support device, each of the   conds elements being substantially identical to one of the first elements and being oriented so that the centers of the dot lines printed by the second printing elements are substantially in the middle between dotted lines printed by first elements adjacent printing.   2. Printer according to claim 1, characterized in that all the first elements are uniformly spaced.   3. Printer according to claim 1, characterized   in that all the second elements are uniform- spaced apart.   4. The printer according to claim 1, characterized   in that the second printing elements se-   are on the same line as the first elements printing.   5. Printer according to claim 4, characterized in that the spacing separating the center of each of the second elements of the first element nearest is substantially uniform and less than a value exceeding 10% the diameter of the body.   6. Printer according to claim 1, characterized   that the centers of the dot lines printed by a pair of adjacent first elements are separated by a distance at least 5% greater than the radius of the points. 7. The method according to claim 1, characterized in that the orientation of each of the first elements is such that a line of dots printed by these elements.   covers a line of dots printed by the second element   adjacent to a distance V that is less than half the diameter of the dots printed by the first and second elements.   8. The printer according to claim 1, characterized   ridiculous in that the line of first elements forms a   angle 6 between 32 and 490 with the direction of pressure.   9. The printer according to claim 4, characterized   in that the center of each of the second elements is offset from the center of the first adjacent element by an absolute angle e between 29 and 49,   measured in relation to the printing direction.   10. The printer according to claim 1, characterized   in that the diameter of the front end of each of the printing elements is smaller than the diameter of the   body measured between the front end and the other end.   11. The printer according to claim 1, characterized   in that each of the printing elements comprises   a ballistic needle having a uniform diameter   body shape along most of its length, with a substantially cylindrical portion of smaller   diameter near the front end.   12. The printer according to claim 11, characterized   in that the length of the substantially cylindrical portion   smaller diameter is less than four times the diameter of the body.   13. The printer according to claim 11, characterized   laughed in that the body diameter is about 0.35nmm   and the diameter of the leading end is about 0.20 mm.   14. Printer, characterized in that it comprises: a print head, a plurality of printing elements carried in the head and each having an end having a maximum effective diameter of printing section which is small relative to the length the corresponding element,   a device for supporting a recording medium   recording in front of the head, a device for actuating each of the elements individually for the printing of an elementary point on the printing medium, and a device for ensuring the relative lateral displacement in a straight line of the head and printing medium, so that the combined repeated control of any one of the elements and the relative lateral displacement causes the printing of a line substantially   rectilinear points on the print medium, the ex-   tremity of each of the printing elements being placed relative to the end of the adjacent element so as to   that the maximum effective diameters of the printing sections   adjacent elements are greater than the   separating the centers from the printed dots by these adjacent elements.   15. The printer according to claim 14, characterized   in that a straight line passing through the corresponding points   simultaneously printed by the adjacent elements makes an angle 0 having an absolute value between   29 and 490 approximately with the printing direction.   Printer according to claim 15, characterized   in that the angle O is equal to sin1 where XD is the diameter of each of the points, V being the overlap of two printed dots in the direction perpendicular to the right by adjacent printing elements, and X being the distance separating the centers from the elements adjacent printing.   17. The printer according to claim 14, characterized   in that the distance separating the centers from two lines printed by adjacent printing elements   is equal to D - V, where D is the diameter of each of   points and V the overlap of the two lines.   A method of printing a symbol that includes a plurality of points, at predetermined locations of a matrix of N locations, in each line, in a first direction, and a plurality of lines in a second direction, the dots being printed by printing elements forming a diagonal angle O with the second direction, each of the points having a   diameter D which is greater than the spacing of the   adjacent to a line in the first direction   but which is less than about twice that space-   said method comprising printing the points of the line at different times determined by the cosine of the angle e multiplied by X, the spacing between   centers of dot printing elements.   19. The method of claim 18, characterized in that it comprises printing the points necessary for the formation of the symbol on about half of the locations in the first direction, on a support   recording, using N / 2 of the printing elements   when these N / 2 print elements scan about half of the surface of the symbol, the offset of the N / 2 print elements in the first direction by a predetermined distance from the recording medium, and the scanning from the rest of the surface   of the symbol by the N / 2 printing elements with impres-   simultaneous collection of the points necessary for printing the   symbol in the rest of the surface of it.   20. The method of claim 19, characterized in that the offset of the N / 2 printing elements is substantially equal to N X sin O. Method according to claim 19, characterized in that the offset of the N / 2 printing elements is   practically equal to (N-1> X sin.0.   22. Printer, characterized in that it comprises: a support device,   a first group of first elements of   uniformly spaced pressure, carried by the support device and each having a certain body diameter and a leading end having a printing area of a certain dimension so that a point having a diameter   predetermined amount shall be printed whenever one of the   printing is ordered, the said elements being   arranged in a first line, the distance between   the centers of the adjacent elements being greater than the diameter of the body, the elements having an orientation such that the centers of two lines of dots printed by two adjacent printing elements are separated by a distance greater than half the diameter of the dot but not not greater than twice the diameter of the point, a first group of actuating devices, in number equal to the number of printing elements but much larger than the diameter of the body, the actuating devices being fixed rigidly to the support device,   a second group of elements supported by the   positive support, each of the second elements of printing   sion being substantially identical to one of the first elements, the second elements forming a second line offset from the first line but parallel to this first line of the first elements, the second elements being uniformly separated by the same distance as the first elements. and having an orientation such that the lines of dots printed by the secondeleménts are parallel to the dotted lines printed by the first elements, and   a second group of mechanisms for   equal in number to that of the second elements of   pressure but much larger section than the body diameter, the second group of actuation devices   being rigidly attached to the support device.   23. The printer according to claim 22, characterized in that the first line of first printing elements and the second line of second printing elements are perpendicular to the dot lines. they print.   24. The printer according to claim 23, characterized   in that the first printing elements are separated by a sufficient distance so that they form visibly separated points when first two   any adjacent printing elements are   each of the second printing elements being arranged to print dots centered on a level which lies midway between the centers of the printed dots by a pair of first elements adjacent printing.   25. The printer according to claim 22, characterized   laughed in that the first line of first elements   of printing and the second line of second   pressure are inclined at an angle between   32 and 490 in relation to the lines of points that they prevail.   26. The printer according to claim 25, characterized   in that the second group of printing elements is offset horizontally and vertically with respect to the   first group of printing elements.